Tag Archives: natural selection

STD Awareness: Which STDs Are Resistant to Antibiotics?

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You’ve probably heard of MRSA, which is pronounced “mersa” and stands for methicillin-resistant Staphylococcus aureus — a strain of bacteria that is resistant to methicillin, as well as pretty much every other antibiotic out there. MRSA is an example of evolution by natural selection — what didn’t kill its ancestors made them stronger, spawning a drug-resistant strain.

There are drug-resistant strains of gonorrhea, trichomoniasis, and syphilis.

Evolution is the force behind life’s diversity. Normally, diversity is a good thing — but when it comes to microbes that cause diseases like gonorrhea, trichomoniasis, and syphilis, these organisms’ ability to evolve new defenses against our antimicrobial drugs isn’t good for us.

STDs have plagued us for millennia, but it wasn’t until the 20th century that we finally developed antibiotics, which gave us a powerful tool against many of our most formidable sexually transmitted foes. Suddenly, scourges like gonorrhea and syphilis could be quickly and easily treated with a dose of penicillin.

Problem solved, right? Nope. Enter evolution by natural selection. Continue reading →

Get Smart About Antibiotics!

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This week we celebrate Get Smart About Antibiotics Week. Antibiotics, or antimicrobials as they are also called, cure bacterial infections by killing bacteria or reducing their ability to reproduce so your own body’s immune system can overcome an infection. Penicillin was the first antibiotic, and was discovered in 1924 by Alexander Fleming. Since its widespread use, beginning in the 1940s, countless lives have been saved from devastating bacterial infections. Talk about a wonder drug!

Improper use of antibiotics can have dangerous consequences.

Since then, different types of antibiotics have been developed to combat many different types of infectious bacteria. Classes of antibiotics include penicillins, cephalosporins, macrolides, fluoroquinolones, aminoglycosides, and others. In each of these classes there are lots of different individual medications. (For example, cephalosporins include the drugs cephalexin, ceftriaxone, cefaclor, and others.) Some antibiotics are broad spectrum, which means they work on many different bacteria. Some are more narrow spectrum, used for specific bacteria.

Antibiotics only work for bacterial infections … not viral infections. They are ineffective at killing viruses. Viral infections include colds, flu, runny noses, most coughs and bronchitis, and sore throats unless they are caused by strep. Sexually transmitted viruses include human papillomavirus (HPV), herpes simplex virus, and HIV. Continue reading →